Gel stabilization in chelate sol-gel preparation of Bi-2223 superconductors

► We increased gel stability at the Bi-2223 preparation using chelating sol-gel method. ► Interaction between used agents (EDTA and TEA) was established using IR spectroscopy. ► Gel decomposition procedure was optimized with respect to the Bi-2223 phase evolution. ► Influence of calcination step on quality of the final samples was also established. ► Superconducting properties and microstructure of the prepared ceramics were evaluated.